JPS60151287A - Manufacture of calcium silicate plate surface-treated with one liquid type aqueous sealer - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a method for producing a calcium silicate plate in which Table In is reinforced. What is the calcium silicate board mentioned here?
It is commonly known as a silicate board, as defined in ISA5418 Asbestos Cement Calcium Silicate Board.

Calcium silicate plates have a surface layer that is Ii! due to its manufacturing method (currently, the roll force method is often used). Cut into pieces
The weak point of removing the surface layer (tint) is eliminated.

It can be painted directly on the calcium silicate board or used as a decorative IE.
When a decorative calcium silicate board is manufactured by adhering (for example, tissue paper) using an adhesive, when a peel test is performed using cellophane tape, the coating film or decorative paper is on the back side of the calcium silicate board. Avoid the phenomenon of peeling off after it has been made to adhere. If these surface thorns occur when removing the material that has been temporarily attached with cellophane tape after being used as a building material for walls or paneling, the result will be very unsightly, so boards that do not have surface thorns should not be used. It is needed.

This invention can remove the surface layer by applying a water-based sealer to a calcium silicate plate. This is probably related to a method for manufacturing treated calcium silicate boards that does not cause any damage. Conventionally, two-component Ida type sealers using epoxy resins or urethane resins have been used to prevent surface peeling of calcium silicate boards. Painting has been done. However, calcium silicate plates treated by this method have three drawbacks as described below.

υ)- is that calcium silicate plate electrodes whose surface has been strengthened with an epoxy resin or urethane resin sealer have extremely poor interval-free properties. It is inconvenient that it is not possible to stock or store it, and that the next steps such as painting and gluing must be carried out immediately after processing (for example, within 30 days). If there is no restriction on the time interval between the treatment or painting and the second treatment or painting, and if a top coat is applied or adhesive is applied after the sealer treatment, the sealer treatment is not required. While the adhesion between the surface of the finished board and the paint or adhesive is sufficient, if the sealer treatment 1 & treated board is left in storage for a long period of time (17A (interval)), the adhesion will deteriorate. There is a phenomenon in which the performance decreases, and the unrestricted (free) performance that does not cause such a decrease is called interval free.

The present invention aims to provide an IVU manufacturing method for calcium silicate plates having this interval-free performance by using a dispersion-type water-based acrylic resin composition.

The second drawback of conventional treatment methods is that most of the conventionally used sealers using epoxy resins and urethane resins are 2e type sealers, which lack stability during painting operations. General two-component epoxy is also used in general (fat and urethane resin paints must not be used together with a hardening agent, otherwise they will not dry out. If so, it can be easily detected as coat 11 and the panicle is in an undried state.

However, the sealer used to strengthen the surface layer of calcium silicate boards impregnates the surface layer of the calcium silicate board, and the a2 part of the sealer enters the inner shell of the surface layer. It is not easy to discover work abnormalities such as forgetting to use hardener 01 when using a sealer using a sealer.In such cases, undried sealer components are only present inside the surface layer. The effect of preventing surface layer peeling cannot be expected at all.

The present invention aims to overcome this drawback by using a dispersed water-based acrylic dispersion and provide a method for producing stable calcium silicate plates that have been subjected to surface reinforcement treatment.

A third disadvantage of conventional treatment methods is that the solvent-based sealers traditionally used are fire hazards.

Most of the factories that manufacture calcium silicate plates do not have equipment that can handle flammable and hazardous materials, so they are connected to the manufacturing process of calcium silicate plates.
It was impossible to apply a solvent-based sealer coating or treatment. For this reason, the conventional sealer treatment process is generally carried out at a factory separate from the calcium silicate plate manufacturing factory or by subcontracting, but the costs involved in handling and transporting the goods are enormous. Become something. Calcium silicate board production lines generally have a monthly production capacity of over 100,000 sheets, and if it were possible to directly connect the sealer coating process to that line, the resulting cost reduction would be enormous. Become something.

The present invention provides a method for producing surface-treated calcium silicate plates at low cost, without the risk of fire, and without the need for any solvent countermeasures, by using an aqueous dispersion sealer that uses water as a diluent. It provides:

Calcium silicate plates that are the object of the present invention are suitable for treatment if they have a bulk specific gravity of 095 to 1.10. If the bulk specific gravity is smaller than this, the absorption of the dispersion will be too large and the method of the present invention will not provide sufficient performance, and if the bulk specific gravity is larger than this, it will be out of the range of normal vascular plates. As mentioned above, the calcium silicate board in the above range has a brittle layer on the surface of the board, so subsequent secondary processing such as painting and adhesion will cause defects such as surface peeling.

The dispersed aqueous acrylic dispersion used in the present invention is prepared by blending a combination of acrylic acid ester monomers, such as butyl acrylate, methyl acrylate, etc., with a small amount of acrylic acid, using a conventional atomization emulsion polymerization method. The average particle size of the dispersion should be 0.1 to improve permeability.
A material with a F of less than μm is suitable.

As a characteristic of the Saida Dice version, it is appropriate that the viscosity be 1000 centipoise or less in order to improve the coating workability during painting. If the viscosity is higher than this, it is not suitable in terms of application work and permeability.

As for the coating method, coating with the above viscosity using a roll coater is suitable, but other methods are also possible. The application area is determined according to the specific gravity of the calcium silicate plate, but the resin solid content of the dispersion is 2 to +29/II+
' range is appropriate. If the amount is less than this range, the treatment will not be effective, and if it is much more than this, not only will there be inconveniences in handling in the next process, etc.
It's not economical either.

After coating, it is preferable to force dry the coated surface, and the heating conditions at that time depend on the heat capacity of the plate to be treated, but
A temperature of 150 to 300°C and a time of 1 to 3 minutes are appropriate.

The applied dispersion penetrates into the inside of the calcium silicate plate from the surface, acts as a binder between the inorganic structures, strengthens the structures three-dimensionally, and prevents the surface layer 14 from peeling off.

Compared to those treated with epoxy resin or urethane resin, calcium silicate plates treated in this way have the advantage of being interval-free in subsequent secondary processing such as gluing and painting, making them suitable for use in buildings. Coarse coating: Can be used without any problems in pasting paper or painting, and can be safely produced and supplied in large quantities at low cost.

Next, the manufacturing method of the present invention will be explained using Example 1.

Example 1-1 Preparation of dispersed water-based acrylic resin dispersion A dispersion was prepared according to the following formulation. Monomer composition Butyl acrylate 13.07 Ri7i parts Methyl methacrylate 12.0 Methacrylic acid 10 11 parts 4+' Riwater 6824 lauryl+llft, acid soda 1.8 polyethylene glycol nonylphenyl ether 22 ammonium persulfate 0.06 Kiai M 4+ (The temperature was raised to 75° C. with stirring, and the monomer composition was dropwise polymerized over 3 hours.

After cooling Ammonia water 02 Pure water 1.5 was added to adjust the viscosity.

At this time, the average diameter of the soybean straw was 007 μyn, and the viscosity was 500 centipoise (20°C).

In substantially the same manner as above, dispersions having average particle diameters of 0, 15, OIO, and 004 μIn, respectively, were prepared by adjusting the emulsifier paste.

The viscosity of four types of dispersions with different particle sizes prepared as described in 1-2- was adjusted by applying them on calcium silicate plates with different bulk specific gravity; 1-1 is the solid content. Two-component urethane resin paint white (door urethane + 100
(manufactured by Higashi 111 Paint Bei J) were painted once after 3 hours, 24 hours, 1 month, 6 months and after baking for 20OClO after treatment, and after drying at room temperature for 1 week. , Base Mouth 1] Test with a knife blade at 2 m, Iban. A peel test was performed by cutting 100 scratches into the substrate in the shape of a shape, pasting cellophane tape on top of the scratches, and carrying out a peel test.

Among these results, the results of the peel test for the test pieces that were left for one month and then painted are shown in Table 41. As an evaluation of resistance to surface layer peeling, the number of stitches remaining without peeling was expressed as a numerator of a fractional formula, and was symbolized as follows.

0/100~69/100 Symbol × 70/100~89/100 △ 90/100~100/100 0 The results in Table 1, the intervals of 3 hours, 24 hours, and 6 months, and the baked ones All of the results showed almost the same results, and it was found that the particle size of the dispersion used in the treatment was suitably 01 μm or less, and the coating viscosity was suitably 100 centipoise or less.

1-3 Next, regarding the relationship between the type of resin solid content applicator and the prickly prevention effect, we investigated the relationship between the resin solid content applicator and the prickly prevention effect by changing the application amount of resin solid content, preparing similar test plates, and applying acrylic as a topcoat at the same intervals. White resin paint (Door Acron JJ Among the results, the results for those coated after an interval of one month are shown in Table 2 using the same evaluation method as in Table 1.

The amount of dispersion applied is 2 to 1 resin solids.
A resistance of about 2 g/m was appropriate. Almost the same results were obtained for other intervals. Based on these results, the coating amount of the dispersion is preferably in the range of 2 to 12 Q/rrl (D) in terms of resin solid content.

As mentioned above, for the treatment of calcium silicate plates with a bulk specific gravity of 0.95 to 11O, the particle size of the dispersion is 0.
．． 1μm or less, resin solid content 2-12g/door, coating viscosity 1
It is appropriate to process at 000 centipoise or less, and by processing under these conditions, it is possible to safely manufacture calcium silicate plates that can be subjected to interval-free secondary processing and do not cause surface peeling even after that. did it.

Patent applicant: Toa Paint Co., Ltd.

Claims (1)

[Claims] Bulk specific gravity 0.95-1. On a lO calcium silicate plate,
A water-based acrylic resin dispersion with an average particle size of 01μ7n or less is coated with a viscosity of 1000
Centipoise or less, application m is 2 to 1 as solid content of buffing fat.
A method for producing a calcium silicate board whose surface layer is reinforced by coating to a coating strength within the range of 2p/++t.